Water-tube boiler.



No. 777,748. I PATENTED DEC. 26, 1904. J. J. ROHAN.

WATER TUBE BOILER.

APPLICATION FILED SEPT. 7, 1904.

9 MODEL- 3 SHEETS-SHEET 1.

ii Cm W'lTzVESSES:

NVENTQR.

No. 7'77,748. PATENTED DEC. 20, 1904. J. J. ROI-IAN.

WATER TUBE BOILBR. APPLICATION FILED SEPT. 7, 1904. no MODEL. 3 SHEETS-SHEET 2.

Pisa,

TOR.

PATENTED DEC. 20, 1904.

J. J. ROHAN.

WATER TUBE BOILER.

APPLIOATIOII FILED SEPT 7, 1904.

3 SHEETS-SHEBT 3.

N0 MODEL.

WITNESSES.-

UNITED STATES Patented December 20, 1904.

PATENT OEEicE.

WATER-TUBE BOILER.

SPECIFICATION formingpart of Letters Patent No. 777,748, dated December 20, 1904. Application filed September '7, 1904. Serial No. 223,579.

To all whom it may concern:

Be it known that I, J AMES J. RoHAN, a citizen of the United States. residing at St. Louis,Mis souri, have invented a new and useful Combination Water-Tube and Fire-Tube Boiler, of which the following is a specification.

My invention relates to combination watertube and fire-tube boilers; and it consists of the novel features herein shown, described, and claimed.

In the drawings, Figure 1 is a front elevation of a combination water-tube and fire-tube boiler constructed in accordance with the principles of my invention, the masonry being shown in section. Fig. 2 is a side elevation as seen looking in the direction indicated by the arrow 2 in Fig. 1, the masonry being broken away to show the details of the boiler construction. Fig. 3 is an enlarged sectional detail on the line 3 30f Fig. 2. Fig. 4 is an enlarged sectional detail showing the trap in the boiler-shell around the ends of the returnflues.

Referring to the drawings in detail, the boiler-shell 5 has the usual dome 6, heads 7 and 8, manholes 9 and 10, and fire-fines 11. The water-heating tubes 12 are connected at their upper ends tothe shell 5 by nipples 13, having right and left threads, said connections being preferably above the water-line and said tubes being connected one half to one side of the shell and the other half to the other side of the shell, each tube being bent to extend across the fire-box 14 and back and said connections being staggered, so that the tubes on one side will pass between the tubes on the other side.

At the lower ends of the Water heating tubes 12 T-fittings 15 are placed, and nipples 16, having right and left threads, connect the T-fittings to the mud-drums 17, the openings 18 through the nipples being greatly reduced relative to the openings through the watertubes. There is a mud-drum for each set of water-tubes, and they are placed at the sides of the fire-box. Each mud-drum has a settling-basin 19. Drain-pipes 20 are placed parallel with the mud-drums 17, outside of the firebox. Pipes 22 connect the mud-drums to the drain-pipes, there being globe-valves 23 in said pipes 22, and pipes 24 connect the settling-basins 19 to the drain-pipes, there being globe-valves 25 in the pipes 24. The returnpipes 26 connect the mud-drums 17 to the bottom of the shell 5, said pipes extending upwardly through the Wall of the shell, so as to form a mud-trap 27 in the shell.

The supply-pipe 28 is connected to the bottom of the shell, so that the feed-water will pass first into the bottom of the shell, where the heavier mud will be precipitated into the trap 27. Then the water will pass through the return-pipes to the mud-drums, where more impurities will be precipitated in the muddrums and washed into the settling-basins. Then the Water will pass through the Watertubes to the top of the shell, said water being converted into steam and discharged directly into the steam-chamber. The water becomes highly heated before reaching the water-tubes, and a very large percentage of the impurities will be precipitated before said water-tubes are reached, and this is a matter of great importance, as heretofore it has been impossible to keep water-heating tubes fromlfilling up. The point at which the water-tubes is attached to the shell is also important. The greater the distance between the receiving end of the return-pipes and discharge ends of the watertubes the greater the draft through the watertubes will be. By connecting the water-tubes to the top of the steam-chamber instead of connecting them at a point below the water-line the steam-chamber is converted into a separator, which allows the water-flow through the watertubes to fall into the shell and allows the steam made in the Water-tubes to pass directly to the steam-dome without passing through the water in the shell, and this greatly increases the current through the water-tubes. It is obvious that a strong current through the water-tubes has a tendency to keep the tubes clean and to discharge all solid matter into the shell, where it will accumulate in the trap 27 The point at which the feed-water is discharged into the shell is also of great importance, as heretofore it has been the practice to run the feed-water in a pipe through the steam-chamber, and this has resulted in cooling the steam and cooling the Water in the feed-pipe, thereby precipitating the mud in the feed-pipe and clogging the pipe. By discharging the feedwater into the bottom of the shell it is first cooked in the shell and not in the feed-water pipe, and it does not cool the steam. The result is that the larger part of the mud and impurities are precipitated in the bottom of the shell, where it is easily removed, and a large part of the remainder of the impurities and mud is precipitated in the mud-drums thereby furnishing comparatively pure water to the water-tubes.

hen it is desired to clean the water-tubes, the globe-valves 23 are opened and the steampressure will blow through the water-tubes by virtue of the difference between the size of the passage through the tubes and the passage through the nipples 16. The water-tubes may be cleaned one at a time without stopping the operation of making steam and running the engine. \Vhen it is desired to clean the mud drums, the globe valves 25 are opened.

Thus it will be seen that I have constructed a combination water tube and firetube boiler in which the impurities are precipitated before reaching the water-tubes, in which the mud may be readily removed from the traps and settling-basins, and in which each watertube may be independently cleaned without stopping the operation of making steam.

I claim 1. In a boiler, a shell; water-tubes connected to the upper part of the shell, mud-drums connected to the lower ends of the water-tubes; settling-basins in the mud-drums; returnpipes connecting the mud-drums to the bottom of the shell; and a blow-off for each watertube; there being a restricted opening between the blow-off and the mud-drum.

2. In a boiler: a shell; water-tubes connected to the upper part of the shell; mud-drums connected to the lower ends of the water-tubes; return pipes connecting the mud drums to the bottom of the shell; and a blow-ofl' for each water-tube,the1 'e being a restricted opening between the blow-off and the mud-drums; substantially as specified.

3. In a boiler: a shell; water-tubes connected to the shell; mud-drums connected to the lower ends of the Water-tubes; return-pipes connecting the mud-drums to the bottom of the shell; and a blow-01f for each water-tube, there being a restricted opening between the blow-ofi' and the mud-drums; substantially as specified.

L. In a boiler: water-tubes; means for establishing a circulation through the watertubes; and a blow off for each water -tube; there being restricted openings in the watertubeson the colder sides of the blow-ofl'; substantially as specified.

JAMES J. ROHAN.

WVitnesses:

CLINTON L. CALDWELL, JOHN A. RoHAN. 

